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Biomedical subjects

K S Bergman

Publications and source records attributed to K S Bergman.

14 recordsLinked to original sources
PubMed1995

Evaluation of oxygenation status during fractionated radiotherapy in human nonsmall cell lung cancers using [F-18]fluoromisonidazole positron emission tomography.

PURPOSE: Recent clinical investigations have shown a strong correlation between pretreatment tumor hypoxia and poor response to radiotherapy. These observations raise questions about standard assumptions of tumor reoxygenation during radiotherapy, which has been poorly studied in human cancers. Positron emission tomography (PET) imaging of [F-18]fluoromisonidazole (FMISO) uptake allows noninvasive assessment of tumor hypoxia, and is amenable for repeated studies during fractionated radiotherapy to systematically evaluate changes in tumor oxygenation. METHODS AND MATERIALS: Seven patients with locally advanced nonsmall cell lung cancers underwent sequential [F-18]FMISO PET imaging while receiving primary radiotherapy. Computed tomograms were used to calculate tumor volumes, define tumor extent for PET image analysis, and assist in PET image registration between serial studies. Fractional hypoxic volume (FHV) was calculated for each study as the percentage of pixels within the analyzed imaged tumor volume with a tumor:blood [F-18]FMISO ratio > or = 1.4 by 120 min after injection. Serial FHVs were compared for each patient. RESULTS: Pretreatment FHVs ranged from 20-84% (median 58%). Subsequent FHVs varied from 8-79% (median 29%) at midtreatment, and ranged from 3-65% (median 22%) by the end of radiotherapy. One patient had essentially no detectable residual tumor hypoxia by the end of radiation, while two others showed no apparent decrease in serial FHVs. There was no correlation between tumor size and pretreatment FHV. CONCLUSIONS: Although there is a general tendency toward improved oxygenation in human tumors during fractionated radiotherapy, these changes are unpredictable and may be insufficient in extent and timing to overcome the negative effects of existing pretreatment hypoxia. Selection of patients for clinical trials addressing radioresistant hypoxic cancers can be appropriately achieved through single pretreatment evaluations of tumor hypoxia.

Aged↗
PubMed1993

Scalp and neck masses.

The evaluation of head and neck masses involves an orderly approach based on a careful history and accurate physical examination. Additional information sometimes is necessary using appropriate laboratory and radiologic investigation. In the vast majority of cases, surgery for biopsy or removal of the mass is required. Accurate preoperative diagnosis may require evaluation by appropriate consultants to avoid unnecessary or inappropriate operations.

Child↗
PubMed1992

Caudate glucose metabolic rate changes with both drug and behavior therapy for obsessive-compulsive disorder.

We used positron emission tomography to investigate local cerebral metabolic rates for glucose (LCMRG1c) in patients with obsessive-compulsive disorder before and after treatment with either fluoxetine hydrochloride or behavior therapy. After treatment, LCMRG1c in the head of the right caudate nucleus, divided by that in the ipsilateral hemisphere (Cd/hem), was decreased significantly compared with pretreatment values in responders to both drug and behavior therapy. These decreases in responders were also significantly greater than right Cd/hem changes in nonresponders and normal controls, in both of whom values did not change from baseline. Percentage change in obsessive-compulsive disorder symptom ratings correlated significantly with the percent of right Cd/hem change with drug therapy and there was a trend to significance for this same correlation with behavior therapy. By lumping all responders to either treatment, right orbital cortex/hem was significantly correlated with ipsilateral Cd/hem and thalamus/hem before treatment but not after, and the differences before and after treatment were significant. A similar pattern was noted in the left hemisphere. A brain circuit involving these brain regions may mediate obsessive-compulsive disorder symptoms.

Adult↗
PubMed1991

Laryngotracheal separation and diversion for complicated esophageal atresia with intractable salivary aspiration.

Chronic salivary aspiration results in progressive pulmonary deterioration. Laryngotracheal separation and diversion were performed to prevent salivary aspiration in a patient following complex repair for esophageal atresia with distal tracheoesophageal fistula. This highly effective and potentially reversible procedure should be considered for treatment of chronic salivary aspiration in selected patients.

Anastomosis, Surgical↗
PubMed1991

Traumatic renal avulsion into the chest: case report.

This is a case report of a patient who survived blunt renal avulsion and herniation of the kidney through a ruptured diaphragm. Symptoms were mild considering the severity of injury. Prompt diagnosis of this unusual combination of injuries was aided by contrast-enhanced computed tomography (CT).

Accidents, Traffic↗
PubMed1988

Pregnancy following repair of vaginal atresia.

The abdomino-perineal-vaginal pull-through operation offers the most anatomically correct reconstruction for patients with vaginal atresia. A 14-year-old girl with vaginal atresia and a persistent urogenital sinus underwent genitourinary reconstruction using this technique. Years later, two planned pregnancies were carried to term and completed by elective cesarean delivery. This is the first case that demonstrates normal vaginal function following abdomino-perineal-vaginal pull-through.

Adolescent↗
PubMed1988

Arteriovenous pH difference--a new index of perfusion.

Measurement of the pH of arterial blood may not reflect early stages of anaerobic metabolism. Since a relationship exists between pH and cellular utilization of oxygen, this study sought to determine whether the difference between arterial and venous pH might serve as a more useful index for estimating the adequacy of tissue perfusion. Dogs were made hypovolemic, and hemodynamic profiles including thermodilution cardiac output were obtained while simultaneous arterial and central venous blood samples were analyzed for pH. Arteriovenous pH difference increased as cardiac index fell. Whenever the arteriovenous pH difference became greater than 0.05 pH units, the cardiac index had fallen below 65% of the baseline values. A difference of 0.05 pH units between arterial and venous blood predicted hypoperfusion in 90% of the animals. With deepening shock the gradient widened, and when resuscitation was effective the arteriovenous pH difference returned toward normal. These data suggest that arteriovenous pH difference may reliably predict clinically significant reductions in cardiac output and cellular perfusion. This finding could be useful in pediatric trauma and critical care settings in which invasive monitoring and direct determination of cardiac output are technically difficult.

Acidosis, Lactic↗
PubMed1988

A pediatric trauma model of continuous hemorrhage.

This report describes a new experimental model of hemorrhage in immature animals. Puppies were subjected to continuous hemorrhage equivalent to 1% of calculated blood volume per minute. In the control group there was no change in mean arterial pressure, central venous pressure, cardiac output, hematocrit, pH, or core temperature. In the experimental group the response to hemorrhage was gradual and in proportion to blood loss until 25% to 30% blood volume reduction. At this critical point, the fall in mean arterial pressure and cardiac output accelerated and death occurred. These observations suggest that the response to blood loss has break points beyond which sudden deterioration is rapid and dramatic. This model of hemorrhage should be useful for future study of the effects of treatment of hemorrhagic shock in immature subjects.

Animals↗
PubMed1986

Oriental cholangitis.

Oriental cholangitis is a progressive hepatic disease characterized by episodic biliary obstruction and sepsis. This is the report of a case of Oriental cholangitis in a nine-year-old girl. Oriental cholangitis should be considered in the differential diagnosis of upper abdominal pain in the susceptible population.

Child↗
PubMed1983

Response to estradiol inhibition of tonic luteinizing hormone secretion decreases during the final stage of puberty in the rhesus monkey.

This investigation was conducted to determine if a decrease in responsiveness to estradiol inhibition of tonic LH secretion occurs in the female rhesus monkey during the late stages of sexual maturation. The study was conducted during the several month period between menarche and first ovulation. Serum LH was measured in postmenarchial females (n = 8) before and after ovariectomy and insertion of estradiol implants that achieved subadult concentrations (10-30 pg/ml) of the steroid. Removal of the ovaries 1-4 months after menarche (31 +/- 1 months) produced a prompt 3- to 5-fold rise in circulating LH. This was prevented by estradiol replacement therapy beginning at ovariectomy. Similarly, insertion of estradiol implants after the castration response was established decreased the high concentrations of circulating LH to preoperative levels where they remained for several months. At 42 +/- 1 months of age, and in the face of unchanging peripheral estradiol, circulating LH rose severalfold in the ovariectomized females (n = 7). At a similar age (44 +/- 2 months, n = 4), ovulations began in untreated females. The results indicate that subadult concentrations of peripheral estradiol which are capable of suppressing LH secretion before the age of first ovulation are ineffective in this regard afterward. This provides compelling evidence for a decrease in estradiol inhibition of tonic LH secretion during puberty in the primate female.

Age Factors↗